package com.alvin;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tomcat.dbcp.pool.impl.GenericKeyedObjectPool.Config;

/**
 * Servlet Filter implementation class LogFilter
 */
public class LogFilter implements Filter {
	Log log = LogFactory.getLog("LogFilter");
    /**
     * Default constructor. 
     */
    public LogFilter() {
    }

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// place your code here

		// pass the request along the filter chain
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		
		long startTime = System.currentTimeMillis();
		String requestURI = req.getQueryString();
		requestURI = req.getQueryString() == null? requestURI: (requestURI + "?"+ req.getQueryString()); 
		
		chain.doFilter(request, response);
		
		long endTime = System.currentTimeMillis();
		log.info(req.getRemoteAddr() +"存取了"+ requestURI +", 總用時"+ (endTime - startTime) +"毫秒。");
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		log.info("啟動 Filter: "+ Config.getfilterName());
	}

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
	}

}
